Tan Bin, Breunig Peter, Arbib Lamia, Kakumu Yuya, Biermann Friederike, Hardes Kornelia, Hefendehl Jasmin, Helfrich Eric J N
Institute for Molecular Bio Science, Goethe University Frankfurt Max-von-Laue Strasse 9 60438 Frankfurt am Main Germany
Institute of Cell Biology and Neuroscience, Goethe University Frankfurt and Buchmann Institute for Molecular Life Sciences 60438 Frankfurt am Main Germany.
Chem Sci. 2025 Aug 6. doi: 10.1039/d5sc03525b.
Cyclic peptides exhibit diverse bioactivities and are distinguished by their enhanced cell permeability, improved proteolytic stability, and increased binding affinity due to their conformational rigidity. Despite significant advancements in peptide synthesis, the production of complex cyclic peptides remains a challenge. Nature has evolved diverse strategies for peptide cyclization, with an ever-growing repertoire of characterized cyclases involved in the biosynthesis of ribosomally synthesized and post-translationally modified peptides (RiPPs). These enzymes convert linear precursor peptides into complex (poly-)cyclic structures. The discovery of the atropopeptides has significantly expanded the chemical diversity of RiPPs with unique (poly-)cyclic structures. In this study, we employed a phylogeny-guided approach to identify a substrate-promiscuous cytochrome P450 macrocyclase that catalyzes the formation of cyclic peptides through atropospecific C-N or C-C bond formation between aromatic amino acid side chains. Combinatorial biosynthetic studies revealed that ScaB encoded in the scabrirubin biosynthetic gene cluster efficiently cyclizes a wide range of atropopeptide precursor peptides. Furthermore, extensive site-directed mutagenesis studies of the tetrapeptide core sequence further expanded the diversity of atropopeptides. Notably, three tested atropopeptides show antiviral activity and one of the non-natural atropopeptides displays anti-inflammatory activity. Our findings establish a broadly substrate-tolerant atropopeptide-modifying P450 as a versatile biocatalyst for the synthesis of bioactive, biaryl-bridged macrocyclic peptides.
环肽具有多种生物活性，其特点是细胞通透性增强、蛋白水解稳定性提高，并且由于构象刚性而具有更高的结合亲和力。尽管肽合成取得了重大进展，但复杂环肽的生产仍然是一项挑战。自然界已经进化出多种肽环化策略，参与核糖体合成和翻译后修饰肽（RiPPs）生物合成的环化酶种类不断增加。这些酶将线性前体肽转化为复杂的（多）环结构。阿托罗肽的发现显著扩展了具有独特（多）环结构的RiPPs的化学多样性。在本研究中，我们采用系统发育引导的方法来鉴定一种底物混杂的细胞色素P450大环化酶，该酶通过芳香族氨基酸侧链之间的阿托罗特异性C-N或C-C键形成催化环肽的形成。组合生物合成研究表明，痂红素生物合成基因簇中编码的ScaB能有效地环化多种阿托罗肽前体肽。此外，对四肽核心序列进行广泛的定点诱变研究进一步扩大了阿托罗肽的多样性。值得注意的是，三种测试的阿托罗肽显示出抗病毒活性，其中一种非天然阿托罗肽具有抗炎活性。我们的研究结果确立了一种广泛耐受底物的阿托罗肽修饰P450作为合成生物活性、联芳基桥连大环肽的通用生物催化剂。
